Turbine control



April 1967 J. H. NANCARROW TURBINE CONTROL 2 Sheets-Sheet 1 Filed Feb. 25. 1966 Z l 4M INVENTOR. f4/M55 M/VCJZwW April 11, 1967 .J. H. NANCARROW 3,313,518

TURB INE CONTROL Filed Feb. 25. 1966 2 Sheets-Sheet 2 United States Patent 3,313,518 TURBINE CONTROL James H. Nancarrow, Torrance, Calif., assignor to The Garrett Corporation, Los Angeles, Calif., a corporation of California Filed Feb. 25, 1966, Ser. No. 530,080 7 Claims. (Cl. 253-52) This invention relates to turbomachinery and more particularly to control means for controlling the fluid flow through machinery of the turbine type having vaneless housings.

In the prior art there have been at least two known methods for controlling the fluid flow through a turbine. One of the well-known methods is to reduce or restrict the fluid flow by throttling action. The disadvantage of the throttling action is that there is a reduction or loss of total energy in the fluid as the fluid passes the throttling restriction. It has been the usual practice in throttling in the prior art to insert butterfly valves which regulate the fluid flow to the Wheel of a turbine. This regulation is very ineflicient because the very definition of throttling is that the total system has suflered a loss of available energy which is equal to the amount of work necessary to bring the system to its original state.

Another prior art method which has been used to control the fluid flow through a turbomachine, especially the turbine type, is to control the direction and velocity of the fluid as it is directed against the wheel. Normally, the control and the direction and flow of fluid is done with a plurality of vanes in the proximity of the wheel, which are simultaneously rotated. This control system is very complex and the cost is high. If the vanes are not rotated simultaneously and in equal amounts it is a possibility that turbulence will be generated in the fluid flow so that the theoretical control of the vanes has been rendered less than fully effective. Thus accurate positioning is of vital importance and in small machines greatly increases the complexity of manufacture.

The present invention is most useful with a turbine having a vaneless housing inasmuch as the nozzles in the vane type turbine modify the velocity and pressure of the fluid immediately prior to the entry into'the wheel. Thus changes in the fluid flow generated by means of nozzles and housing configurations upstream of the vanes is not adequately reflected in the work output of the turbine due to the operation of the vanes immediately prior to the wheel.

It is an object of the invention to provide a simple mechanism to control the fluid flow in a turbomachine of the turbine type in response to a plurality of operating parameters.

It is a further object of this invention to provide a control system to control the fluid flow in turbines Whereby there is very little or no loss of total energy over a predetermined operating range compared to the energy loss occurring in a throttling control system.

It is yet a further object of this invention to provide an economical control system which may be actuated by any well-known hydraulic, pneumatic, mechanical or electrical means to control the fluid flow in a turbine in response to a plurality of operating parameters.

It is another object of this invention to provide a control mechanism for controlling fluid flow in a turbine which is especially adaptable to a plurality of vaneless types of turbines.

It is a still further object of this invention to provide a control mechanism for controlling the fluid flovv in turbines which is capable of having its range of control extended by the addition of a bypass means around the turbine wheel called a Waste gate.

3,313,518 Patented Apr. 1 l, 1967 ice These and other objects of this invention will become apparent when the following detailed description is read in conjunction with the drawings in which:

FIG. 1 is a side elevation view with a partial cross section of one embodiment of this invention with a schematic representation of a control system useful with this invention;

FIG. 2 is a sectional view through plane 22 of FIG. 1;

FIG. 3 is a partial side elevation view of the control mechanism of FIG. 1 with the addition of the waste gate control;

FIG. 4 is a sectional view through plane 44 of 1 16.3;

FIG. 5 is a partial side elevation view of this invention embodied in a meridionally divided housing;

FIG. 6 is a sectional view through plane 6-6 of FIG. 5; and

FIG. 7 is a side elevation view of this invention embodied in a segmented turbine.

Referring now to FIG. 1, there is shown therein a turbine including a vaneless housing 10 of the scroll or volute type. Turbine housing 10 is illustrated as being of the volute type and includes an inlet section 11, an entrance portion 12, a tongue 13 and the volute portion 14. The volute portion extends substantially from the control areas A and B to the tip diameter of the wheel 15. The entrance portion 12 may be defined as that portion of the housing extending from the inlet 11 to the areas A and B which describe the beginning of the volute portion 14.

The turbornachine has a wheel 15 including a plurality of blades thereon. The wheel 15 is rotated by the passage of fluid from the inlet to the outlet of said machine through the blades. The invention includes a movable vane means 16 which in the preferred embodiment is pivoted about the pivot point or shaft 17. The vane means 16 is an elongated arcuate member generally conforming to the arcuate configuration of the housing and provides for the necessary amount of movement within the housing to generate the requisite control.

The sensing means 18 actuates control means 19. The sensing means 18 may be any well-known means to sense changes in the value of any one of a plurality of desired operating parameters. The sensing means may sense an absolute value or it may sense the difference or change in the parameters from a predetermined value or level. The Sensing means 13 provides a signal to the control means 19 and the control means 19 in response to this signal moves members 20 in the direction and through the distance denoted by the signal. The movable members 20 operate to rotate the vane means 16 about its pivot point 17 through the lever arm 21.

In a typical utilization of the turbomachine of this invention as a supercharger, a supply of pressurized air or gas is connected to the inlet 11. The air or gas is passed from the inlet through the housing to the blades of the wheel 15 and thus to the outlet of the turbomachine. The speed of rotation of the shaft of the wheel 15 is determined by the energy applied to the wheel and the load being driven by the shaft. The scroll of the turbine of this invention when utilized as a turbo-supercharger must necessarily 'be defined so that the inner surface of the volute 14 plus the vane mechanism 16 delivers to the wheel 15 the desired gas weight flow and head characteristics. When utilized in a turbo-supercharger, the control system of this invention operates to provide controlled variable air flow to an engine Within the operating confines of the turbo-supercharger. The particular turbo-supercharger will normally be designed to operate between predetermined operating limits using, for example, the corrected weight flow of gas or air versus the ratio of the inlet pressure to the outlet pressure as characteristics. The control system of this invention makes it possible to vary the corrected weight flow of air so as to provide eflicient operation of the turbine with a variety of variable parameters. The turbine inlet and/or compressor outlet pressures may be maintained relatively constant with a plurality of variations in total fluid flow to the turbine without throttling the turbine. By sensing different parameters and for different uses of this invention the total fluid flow may be maintained constant with a plurality of variations in turbine inlet and/ or compressor outlet pressures.

The movable pivot 17 can be located at any point on the vane 16 so that movement about that point simultaneously reduces or increases both areas A and B or so that movement either reduces or increases A and B individually. The vane means 16 is inserted into the turbomachine in proximity to the entrance portion 12. The vane means 16 is supported by a support means 26 which is also a cover means. The vane means must be designed to move within the housing scroll so as to control the fluid flow as the vane interacts with the shape of the volute. The vane mechanism 16 co-acts with the volute 14 to assure that the individual fluid flow through the areas A and B are recombined with a minimum of turbulence. The fluid is accelerated by passing through the control areas A and B. The volute may normally be designed to maintain the angular momentum of the fluid by increasing the angular velocity of the flow stream as it moves toward the center of the wheel.

FIG. 2 is a sectional view showing the position of the vane 16 within the housing 10. The control pivot point 17 and the lever arm 21 are actuated as shown in FIG. 1 so that the vane 16 is rotated in an are about the pivot point 17.

FIG. 3 is a variation of the embodiment shown in FIG. 1 in which a waste gate or fluid escape area 31 is provided in the housing 10. The fluid escape area or waste gate, as it is often referred to, is located in the housing lltl so that as the vane 16 is rotated a predetermined amount about the pivot point 17, the waste gate 311 is gradually opened. As waste gate 31 is smoothly and gradually exposed to the input fluid pressure, the fluid can be bled ofl; into the downstream discharge of the turbine. By bleeding off the fluid through the waste gate 31, it is possible to further limit the operating parameters and extend the control of this invention over the speed or output of the turbomachine.

FIG. 4 is a sectional view through plane 4-4 of FIG. 3 and illustrates further the waste gate 31. The movement of the vane 16 in a vertical direction in FIG. 4 is accomplished by rotating the vane 16 about the center of rotation or pivot point 17. The vertical movement will smoothly and gradually open the waste gate 311 as the point of maximum control of the turbomachine is achieved through the action of the vane 16 co-acting with the housing It). When the vane 16 has accomplished its controlling function by rotation about the pivot point and the areas A and B have been enlarged, the waste gate 311 is fully uncovered and bleeds off fluid which is not needed to drive the turbine.

FIG. 5 depicts the invention utilized in a turbine having a meridionally divided housing. The housing comprises inlet llll, two similar entrance portions 12. The control mechanism now consists of control vanes 16 which are rotated about the pivot point 117 to vary the areas A and B. The fluid flow to the wheels of the turbomachinery is again controlled by the motion of the vane 16. It is possible for the vanes 16 to carry part of the dividing wall 61 so that in effect you have an intrinsic vane 16. It will be obvious to those skilled in the art that two vanes 16 which are operated together or the intrinsic vane could be utilized to perform the control function of this invention in a meridionally divided housing.

As shown in FIG. 6, the housing 10 has a meridional or dividing wall 61 which may extend substantially around the circumference of the volute of the housing. Thus the vane 16 may be divided into two sections as shown in FIG. 6. The portions of the wall 61 related to the vanes in the intrinsic embodiment must fit tightly within the remainder of the wall to prevent leakage of gas from one side of the housing to the other. As described hereinabove, the variation of areas A and B by movement of vane or vanes 16 will control the fluid flow through the turbomachine.

FIG. 7 depicts a turbine having a segmentally divided housing. The housing consists of two inlets 11, each supplying air to approximately one half of the total number of blades of the wheel 15 at any one time. The segmentally divided housing includes two volutes, two tongues and two control vanes. The two control vanes act in conjunction or unison so that the fluid flow is controlled simultaneously in both segments of the turbomachinery.

It will be apparent to those skilled in the art that the novel principles of the invention disclosed herein will suggest various other modifications and applications of the same, for example, use in controlling the flow in a compressor including a vaneless volute type housing. It is accordingly desired that the present invention shall not be limited to the specific embodiment thereof described herein.

What is claimed:

ll. An air reaction type turbomachine comprising:

a housing, said housing including an entrance portion and having a flow area in the configuration of a volute;

a wheel having blades thereon; inlet means for conmeeting said entrance portion of said housing to a source of fluid; and

means for varying the flow area of said housing, said variable flow areas delivering the total fluid flow of said inlet to said wheel, said means comprising a movable vane means dividing said flow area into two flow areas, said vane means being an arcuate member generally conforming to the arcuate configuration of said housing and having a portion thereof extending int-o said entrance portion.

2. An air reaction type turbomachine comprising:

a housing, said housing including an entrance portion and having a flow area in the configuration of a volute;

a wheel having blades there-on, inlet means for connecting said entrance portion of said housing to a source of fluid gas;

means for varying the flow area of said housing, said means comprising a movable vane means dividing said flow area into two flow areas, said vane means being an arcuate member generally conforming to the arcuate configuration of said housing and having a portion thereof extending into said entrance portion; and

means for moving said vane means whereby the individual flow areas are varied thereby controlling the flow of fluid substantially without loss of total energy over a predetermined operating range.

3. An air reaction type turbomachine comprising:

a vaneless housing including an entrance portion, the flow area of said housing having the configuration of a volute;

a wheel having blades thereon, inlet means for connecting said entrance portion of said housing to a source of fluid;

means for varying the flow area of said housing, said means comprising a movable vane means, said vane means being an arcuate member generally conforming to the arcuate configuration of said housing and having a portion thereof extending into said entrance portion;

se si g ans for sensing control parameters; and

means including control means responsive to said sensing means for actuating said control means to move said vane means whereby the total fluid flow to said wheel is controlled over the range of operating characteristics of said machine.

4. An air reaction type turbomachine comprising:

a housing, the flow area of said housing including an inlet, an entrance and a volute portion;

a Wheel having blades thereon, said inlet connecting said entrance of said housing to a fluid source;

means for varying the flow area of said housing, said last-mentioned means comprising a movable vane means, said vane means being an arcuate member generally conforming to the arcuate configuration of said housing and positioned in said housing in the proximity of said entrance and the beginning portions of said volute and having a portion thereof extending into said entrance to divide said housing into two flow areas; and

means for moving said vane means whereby the individual flow areas are varied thereby controlling the total fluid flow to said wheel.

5. An air reaction type turbomachine comprising:

a housing, the flow area of said housing including an inlet, an entrance and a volute-portion;

a wheel having blades thereon, said inlet connecting said entrance of said housing to a source of working fluid;

means for varying the flow area of said housing, said last-mentioned means comprising a movable vane means, said vane means positioned in said housing and extending into said entrance and the beginning portions of said volute to divide said housing into two flow areas, said vane means being an arcuate member generally conforming to the arcuate configuration of said housing; said vane means and said volute combining the individual fluid flows from each of said fiow areas into a single flow to said wheel with a minimum of turbulence; and

control means for moving said vane means a predetermined amount thereby varying the individual flow areas between said housing and said vane means to control the total fluid flow to said wheel.

6. An air reaction type turbomachine comprising:

a housing, the flow area of said housing including an inlet, an entrance and a volute portion;

a wheel having blades thereon, said inlet connecting said housing to a source of working fluid;

means for varying the flow area of said housing, said last-mentioned means comprising a movable vane means, said v-ane means positioned in said housing in the proximity of said entrance and the beginning portions of said volute to divide said housing into two flow areas, said vane means being an arcuate member generally conforming to the arcuate configuration of said housing, said vane means and said volute combining the individual fluid flows from each of said flow areas into a single flow to said wheel with a minimum of turbulence;

means in said housing juxtaposed to said vane means and actuated by the movement of said vane means to provide for the bleeding of said fluid from said flow area; and

control means for moving said vane means a predetermined amount thereby varying the individual flow areas between said housing and said vane means to control the total fluid flow to said wheel.

7. An air reaction type turbomachine comprising:

a housing, the flow area of said housing including an inlet, an entrance, a tongue, and a volute portion; a wheel having blades thereon;

said inlet connecting said housing to a source of working fluid;

means for varying the flow area of said housing, said last mentioned means comprising a moveable vane means;

said vane means positioned in said housing in the proximity of said entrance and overlapping at least a portion of said tongue means and extending into the beginning portions of said volute to divide said housing into two flow areas,

said vane means and said volute combining the individual fluid flows from each of said flow areas into a single flow to said wheel with a minimumof turbulence; means in said housing juxtaposed to said vane means and the tongue portion of said housing,

said last mentioned means actuated by the movement of said vane means to provide for the bleeding of said fluid from said flow area; and control means for moving said vane means a predetermined amount thereby varying the individual flow areas between said housing and said vane means to control the total fluid flow to said wheel.

References Cited by the Examiner UNITED STATES PATENTS 98,741 1/1870 Chase 253128 1,955,683 4/1934 Reiffenstein 253124 2,026,436 12/1935 Reifi'enstein 253-124 2,944,786 7/1960 Angell et a1. 253-52 X MARTIN P. SCHWADRON, Primary Examiner.

EVERETTE A. POWELL, Examiner. 

1. AN AIR REACTION TYPE TURBOMACHINE COMPRISING: A HOUSING, SAID HOUSING INCLUDING AN ENTRANCE PORTION AND HAVING A FLOW AREA IN THE CONFIGURATION OF A VOLUTE; A WHEEL HAVING BLADES THEREON; INLET MEANS FOR CONNECTING SAID ENTRANCE PORTION OF SAID HOUSING TO A SOURCE OF FLUID; AND MEANS FOR VARYING THE FLOW AREA OF SAID HOUSING, SAID VARIABLE FLOW AREAS DELIVERING THE TOTAL FLUID FLOW OF SAID INLET TO SAID WHEEL, SAID MEANS COMPRISING A MOVABLE VANE MEANS DIVIDING SAID FLOW AREA INTO TWO FLOW AREAS, SAID VANE MEANS BEING AN ARCUATE MEMBER GENERALLY CONFORMING TO THE ARCUATE CONFIGURATION OF SAID HOUSING AND HAVING A PORTION THEREOF EXTENDING INTO SAID ENTRANCE PORTION. 